title: UV photo-dissociation and photodesorption of N2O on Ag(111).
abstract: Nanosecond laser induced photoreactions of N2O adsorbed on Ag(111) have been studied by temperature programmed desorption (TPD) and mass-selected, angle-dependent time-of-flight (MS-TOF) measurements of neutral desorbing particles. N2O molecules in the first monolayer are thermally inert but photo-dissociate into N2 + O, or photodesorb molecularly or dissociatively, at photon energies above 3.5 eV. We have found that TOF spectra of photodesorbed N2 as well as of N2O measured at hν = 4.7 eV consist of two velocity components. The desorption flux of the fastest component of N2O peaks ∼ 25° off the surface normal, whereas the others are directed in the surface normal. Origins and photo-excitation as well as photodesorption mechanisms of the N2O and N2 signals are discussed.
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
authors.forename: Ki Hyun
authors.initials: KH
authors.lastname: Kim
authors.forename: Kazuo
authors.initials: K
authors.lastname: Watanabe
authors.forename: Dietrich
authors.initials: D
authors.lastname: Menzel
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Freund